Associations Between the Wisconsin Inventory of Smoking Dependence Motives and Regional Brain Volumes in Adult Smokers

Introduction The Wisconsin Inventory of Smoking Dependence Motives (WISDM-68) is a 68-item questionnaire to assess nicotine dependence as a multifactorial construct based on 13 theoretically derived smoking motives. Chronic smoking is associated with structural changes in brain regions implicated in the maintenance of smoking behavior; however, associations between brain morphometry and the various reinforcing components of smoking behavior remain unexamined. The present study investigated the potential association between smoking dependence motives and regional brain volumes in a cohort of 254 adult smokers. Aims and Methods The WISDM-68 was administered to participants at the baseline session. Structural magnetic resonance brain imaging (MRI) data from 254 adult smokers (M-age = 42.7 & PLUSMN; 11.4) with moderate to severe nicotine dependence (M-FTND = 5.4 & PLUSMN; 2.0) smoking for at least 2 years (M-years = 24.3 & PLUSMN; 11.8) were collected and analyzed with Freesurfer. Results Vertex-wise cluster analysis revealed that high scores on the WISDM-68 composite, secondary dependence motives (SDM) composite, and multiple SDM subscales were associated with lower cortical volume in the right lateral prefrontal cortex (cluster-wise p's < .035). Analysis of subcortical volumes (ie, nucleus accumbens, amygdala, caudate, and pallidum) revealed several significant associations with WISDM-68 subscales, dependence severity (Fagerstrom Test for Nicotine Dependence), and overall exposure (pack-years). No significant associations between cortical volume and other nicotine dependence measures or pack-years were observed. Conclusions Results suggest that smoking motives may play a larger role in cortical abnormalities than addiction severity and smoking exposure per se, whereas subcortical volumes are associated with smoking motives, addiction severity, and smoking exposure. Implications The present study reports novel associations between the various reinforcing components of smoking behavior assessed by the WISDM-68 and regional brain volumes. Results suggest that the underlying emotional, cognitive, and sensory processes that drive non-compulsive smoking behaviors may play a larger role in gray matter abnormalities of smokers than smoking exposure or addiction severity.